The invention relates to a method for determining the axle geometry of a vehicle.
The practice of applying marks to the surface of a tyre is known from the EP 0 280 941 AI. These marks reflect light that impinges upon them. According to the description, diffuse or structured light can be projected on the tyres and thus also on the marks. Provision is also made for a camera with which, using the method of triangulation, the orientation of the tyre surface can be determined. Effects such as raised lettering on the tyre surface can be compensated for by means of analysis methods. If wheel alignment is performed on a rotating wheel (dynamic wheel alignment), effects can be compensated for that may occur if, on account of the wheel's not having been fitted exactly, the wheel axle is not exactly perpendicular to the wheel plane. Measurements obtained during dynamic wheel alignment are averaged accordingly.
The DE 103 35 829 AI describes a method of determining a vehicle's axle geometry in which flat-coded light is projected on an area of the vehicle wheel and the diffusely reflected light is captured from a direction other than the direction of projection in order to determine from the captured light the three-dimensional surface coordinates for the topographical image of the wheel face. This method permits, among other things, determination of the wheel plane and hence of the wheel track and camber. As light source, a beamer is used that projects different colours and/or geometric patterns spread over an area.